MOTOROLA MRF141

Order this document
by MRF141/D
SEMICONDUCTOR TECHNICAL DATA
The RF MOSFET Line
N–Channel Enhancement–Mode MOSFET
Designed for broadband commercial and military applications at frequencies
to 175 MHz. The high power, high gain and broadband performance of this
device makes possible solid state transmitters for FM broadcast or TV channel
frequency bands.
• Guaranteed Performance at 30 MHz, 28 V:
Output Power — 150 W
Gain — 18 dB (22 dB Typ)
Efficiency — 40%
150 W, 28 V, 175 MHz
N–CHANNEL
BROADBAND
RF POWER MOSFET
• Typical Performance at 175 MHz, 50 V:
Output Power — 150 W
Gain — 13 dB
• Low Thermal Resistance
• Ruggedness Tested at Rated Output Power
• Nitride Passivated Die for Enhanced Reliability
D
G
CASE 211–11, STYLE 2
S
MAXIMUM RATINGS
Rating
Symbol
Value
Unit
Drain–Source Voltage
VDSS
65
Vdc
Drain–Gate Voltage
VDGO
65
Vdc
VGS
± 40
Vdc
Drain Current — Continuous
ID
16
Adc
Total Device Dissipation @ TC = 25°C
Derate above 25°C
PD
300
1.71
Watts
W/°C
Storage Temperature Range
Tstg
– 65 to +150
°C
TJ
200
°C
Symbol
Max
Unit
RθJC
0.6
°C/W
Gate–Source Voltage
Operating Junction Temperature
THERMAL CHARACTERISTICS
Characteristic
Thermal Resistance, Junction to Case
NOTE — CAUTION — MOS devices are susceptible to damage from electrostatic charge. Reasonable precautions in handling and
packaging MOS devices should be observed.
REV 8
RF DEVICE DATA
MOTOROLA
Motorola, Inc. 1997
MRF141
1
ELECTRICAL CHARACTERISTICS (TC = 25°C unless otherwise noted)
Characteristic
Symbol
Min
Typ
Max
Unit
V(BR)DSS
IDSS
65
—
—
Vdc
—
—
5.0
mAdc
IGSS
—
—
1.0
µAdc
VGS(th)
VDS(on)
1.0
3.0
5.0
Vdc
0.1
0.9
1.5
Vdc
gfs
5.0
7.0
—
mhos
Ciss
Coss
—
350
—
pF
Output Capacitance (VDS = 28 V, VGS = 0, f = 1.0 MHz)
—
420
—
pF
Reverse Transfer Capacitance (VDS = 28 V, VGS = 0, f = 1.0 MHz)
Crss
—
35
—
pF
Gps
16
—
20
10
—
—
dB
η
40
45
—
%
IMD(d3)
IMD(d11)
ψ
—
—
– 30
– 60
– 28
—
OFF CHARACTERISTICS (1)
Drain–Source Breakdown Voltage (VGS = 0, ID = 100 mA)
Zero Gate Voltage Drain Current (VDS = 28 V, VGS = 0)
Gate–Body Leakage Current (VGS = 20 V, VDS = 0)
ON CHARACTERISTICS (1)
Gate Threshold Voltage (VDS = 10 V, ID = 100 mA)
Drain–Source On–Voltage (VGS = 10 V, ID = 10 A)
Forward Transconductance (VDS = 10 V, ID = 5.0 A)
DYNAMIC CHARACTERISTICS (1)
Input Capacitance (VDS = 28 V, VGS = 0, f = 1.0 MHz)
FUNCTIONAL TESTS
Common Source Amplifier Power Gain, f = 30; 30.001 MHz
(VDD = 28 V, Pout = 150 W (PEP), IDQ = 250 mA) f = 175 MHz
Drain Efficiency
(VDD = 28 V, Pout = 150 W (PEP), f = 30; 30.001 MHz,
IDQ = 250 mA, ID (Max) = 5.95 A)
Intermodulation Distortion (1)
(VDD = 28 V, Pout = 150 W (PEP), f = 30 MHz,
f2 = 30.001 MHz, IDQ = 250 mA)
Load Mismatch
(VDD = 28 V, Pout = 150 W (PEP), f1 = 30; 30.001 MHz,
IDQ = 250 mA, VSWR 30:1 at all Phase Angles)
dB
No Degradation in Output Power
CLASS A PERFORMANCE
Intermodulation Distortion (1) and Power Gain
GPS
—
(VDD = 28 V, Pout = 50 W (PEP), f1 = 30 MHz,
IMD(d3)
—
f2 = 30.001 MHz, IDQ = 4.0 A)
IMD(d9 – 13)
—
NOTE:
1. To MIL–STD–1311 Version A, Test Method 2204B, Two Tone, Reference Each Tone.
BIAS +
0 – 12 V
–
23
– 50
– 75
R4
C5
C6
R1
RF INPUT
R3
D.U.T.
C8
C7
T2
C4
L2
C9
–
dB
+
+
L1
C11
—
—
—
C10
28 V
–
RF
OUTPUT
C2
T1
C3
R2
C2, C5, C6, C7, C8, C9 — 0.1 µF Ceramic Chip or
Monolythic with Short Leads
C3 — Arco 469
C4 — 820 pF Unencapsulated Mica or Dipped Mica
with Short Leads
C10 — 10 µF/100 V Electrolytic
C11 — 1 µF, 50 V, Tantalum
C12 — 330 pF, Dipped Mica (Short leads)
C12
L1 — VK200/4B Ferrite Choke or Equivalent, 3.0 µH
L2 — Ferrite Bead(s), 2.0 µH
R1, R2 — 51 Ω/1.0 W Carbon
R3 — 1.0 Ω/1.0 W Carbon or Parallel Two 2 Ω, 1/2 W Resistors
R4 — 1 kΩ/1/2 W Carbon
T1 — 16:1 Broadband Transformer
T2 — 1:25 Broadband Transformer
Board Material — 0.062″ Fiberglass (G10),
1 oz. Copper Clad, 2 Sides, er = 5
Figure 1. 30 MHz Test Circuit (Class AB)
MRF141
2
MOTOROLA RF DEVICE DATA
TYPICAL CHARACTERISTICS
VGS, GATE-SOURCE VOLTAGE (NORMALIZED)
I D, DRAIN CURRENT (AMPS)
100
10
TC = 25°C
1
1
10
VDS, DRAIN–TO–SOURCE VOLTAGE (VOLTS)
100
1.04
1.03
1.02
1.01
1
0.99
0.98
0.97
0.96
0.95
0.94
0.93
0.92
0.91
0.9
– 25
Figure 2. DC Safe Operating Area
ID = 5 A
4A
2A
1A
0.5 A
0.25 A
0
100
75
Figure 3. Gate–Source Voltage versus
Case Temperature
200
0
f T, UNITY GAIN FREQUENCY (MHz)
2000
C, CAPACITANCE (pF)
VDS = 20 V
10 V
1000
Coss
Ciss
200
Crss
0
0
2
4
6
8
10
12
14
ID, DRAIN CURRENT (AMPS)
16
18
20
0
20
5
10
15
25
Figure 5. Capacitance versus
Drain–Source Voltage
30
Pout , OUTPUT POWER (WATTS)
300
25
20
VDD = 28 V
IDQ = 250 mA
Pout = 150 W
15
10
200
f = 175 MHz
VDD = 28 V
IDQ = 250 mA
100
00
5
10
15
2
10
100
200
20
25
300
200
f = 30 MHz
VDD = 28 V
IDQ = 250 mA
100
5
20
VDS, DRAIN–SOURCE VOLTAGE (VOLTS)
Figure 4. Common Source Unity Gain Frequency
versus Drain Current
GPS , POWER GAIN (dB)
25
50
TC, CASE TEMPERATURE (°C)
0
0
1
2
3
4
5
f, FREQUENCY (MHz)
Pin, INPUT POWER (WATTS)
Figure 6. Power Gain versus Frequency
Figure 7. Output Power versus Input Power
MOTOROLA RF DEVICE DATA
MRF141
3
TYPICAL CHARACTERISTICS
320
f = 30 MHz
IDQ = 250 mA
280
Pout , OUTPUT POWER (WATTS)
Pout , OUTPUT POWER (WATTS)
320
240
Pin = 4 W
200
160
2W
120
1W
80
f = 175 MHz
IDQ = 250 mA
280
240
200
Pin = 20 W
160
120
14 W
80
8W
40
40
0
12
14
16
18
20
22
24
26
0
12
28
14
16
18
20
22
24
26
SUPPLY VOLTAGE (VOLTS)
Figure 8. Output Power versus Supply Voltage
Figure 9. Output Power versus Supply Voltage
IMD, INTERMODULATION DISTORTION (dB)
SUPPLY VOLTAGE (VOLTS)
28
25
d3
35
d5
45
IDQ = 250 mA
55
VDD = 28, f = 30 MHz, TONE SEPARATION = 1 kHz
25
d3
35
45
55
d5
0
20
40
60
IDQ = 500 mA
80
100
120
140
160
180
200
Pout, OUTPUT POWER (WATTS)
Figure 10. IMD versus Pout (PEP)
MRF141
4
MOTOROLA RF DEVICE DATA
Zo = 10 Ω
VDD = 28 V
IDQ = 250 mA
Pout = 150 W PEP
ZOL* = Conjugate of the optimum load impedance
ZOL* = into which the device output operates at a
ZOL* = given output power, voltage and frequency.
30
15
100
7.5
Zin
4
30
2
150
100
2
f = 175 MHz
ZOL* f = 175 MHz
Figure 11. Input and Output Impedances
RFC1
+ 28 V
+
BIAS
0 – 12 V
R1
C10
L4
–
C11
+
C4
C5
R3
C1
DUT
L3
C9
L2
L1
RF
OUTPUT
RF INPUT
C2
C3
R2
C1, C2, C8 — Arco 463 or equivalent
C3 — 25 pF, Unelco
C4 — 0.1 µF, Ceramic
C5 — 1.0 µF, 15 WV Tantalum
C6 — 25 pF, Unelco J101
C7 — 25 pF, Unelco J101
C9 — Arco 262 or equivalent
C10 — 0.05 µF, Ceramic
C11 — 15 µF, 35 WV Electrolytic
C6
C7
C8
L1 — 3/4″, #18 AWG into Hairpin
L2 — Printed Line, 0.200″ x 0.500″
L3 — 7/8″, #16 AWG into Hairpin
L4 — 2 Turns, #16 AWG, 5/16 ID
RFC1 — 5.6 µH, Molded Choke
RFC2 — VK200–4B
R1 — 150 Ω, 1.0 W Carbon
R2 — 10 kΩ, 1/2 W Carbon
R3 — 120 Ω, 1/2 W Carbon
Figure 12. 175 MHz Test Circuit (Class AB)
MOTOROLA RF DEVICE DATA
MRF141
5
RF POWER MOSFET CONSIDERATIONS
MOSFET CAPACITANCES
The physical structure of a MOSFET results in capacitors
between the terminals. The metal anode gate structure determines the capacitors from gate–to–drain (Cgd), and gate–
to–source (C gs ). The PN junction formed during the
fabrication of the MOSFET results in a junction capacitance
from drain–to–source (Cds).
These capacitances are characterized as input (Ciss), output (Coss) and reverse transfer (Crss) capacitances on data
sheets. The relationships between the inter–terminal capacitances and those given on data sheets are shown below. The
Ciss can be specified in two ways:
1. Drain shorted to source and positive voltage at the gate.
2. Positive voltage of the drain in respect to source and zero
volts at the gate. In the latter case the numbers are lower.
However, neither method represents the actual operating conditions in RF applications.
DRAIN
Cgd
GATE
Cds
Cgs
Ciss = Cgd = Cgs
Coss = Cgd = Cds
Crss = Cgd
SOURCE
LINEARITY AND GAIN CHARACTERISTICS
In addition to the typical IMD and power gain data presented, Figure 4 may give the designer additional information
on the capabilities of this device. The graph represents the
small signal unity current gain frequency at a given drain current level. This is equivalent to fT for bipolar transistors.
Since this test is performed at a fast sweep speed, heating of
the device does not occur. Thus, in normal use, the higher
temperatures may degrade these characteristics to some extent.
DRAIN CHARACTERISTICS
One figure of merit for a FET is its static resistance in the
full–on condition. This on–resistance, VDS(on), occurs in the
linear region of the output characteristic and is specified under specific test conditions for gate–source voltage and drain
current. For MOSFETs, VDS(on) has a positive temperature
coefficient and constitutes an important design consideration
at high temperatures, because it contributes to the power
dissipation within the device.
GATE CHARACTERISTICS
The gate of the MOSFET is a polysilicon material, and is
electrically isolated from the source by a layer of oxide. The
input resistance is very high — on the order of 109 ohms —
resulting in a leakage current of a few nanoamperes.
Gate control is achieved by applying a positive voltage
slightly in excess of the gate–to–source threshold voltage,
VGS(th).
Gate Voltage Rating — Never exceed the gate voltage
rating. Exceeding the rated VGS can result in permanent
damage to the oxide layer in the gate region.
Gate Termination — The gate of this device is essentially
capacitor. Circuits that leave the gate open–circuited or floatMRF141
6
ing should be avoided. These conditions can result in turn–
on of the device due to voltage build–up on the input
capacitor due to leakage currents or pickup.
Gate Protection — This device does not have an internal
monolithic zener diode from gate–to–source. If gate protection is required, an external zener diode is recommended.
Using a resistor to keep the gate–to–source impedance
low also helps damp transients and serves another important
function. Voltage transients on the drain can be coupled to
the gate through the parasitic gate–drain capacitance. If the
gate–to–source impedance and the rate of voltage change
on the drain are both high, then the signal coupled to the gate
may be large enough to exceed the gate–threshold voltage
and turn the device on.
HANDLING CONSIDERATIONS
When shipping, the devices should be transported only in
antistatic bags or conductive foam. Upon removal from the
packaging, careful handling procedures should be adhered
to. Those handling the devices should wear grounding straps
and devices not in the antistatic packaging should be kept in
metal tote bins. MOSFETs should be handled by the case
and not by the leads, and when testing the device, all leads
should make good electrical contact before voltage is applied. As a final note, when placing the FET into the system it
is designed for, soldering should be done with a grounded
iron.
DESIGN CONSIDERATIONS
The MRF141 is an RF Power, MOS, N–channel enhancement mode field–effect transistor (FET) designed for HF and
VHF power amplifier applications.
Motorola Application Note AN211A, FETs in Theory and
Practice, is suggested reading for those not familiar with the
construction and characteristics of FETs.
The major advantages of RF power MOSFETs include
high gain, low noise, simple bias systems, relative immunity
from thermal runaway, and the ability to withstand severely
mismatched loads without suffering damage. Power output
can be varied over a wide range with a low power dc control
signal.
DC BIAS
The MRF141 is an enhancement mode FET and, therefore, does not conduct when drain voltage is applied. Drain
current flows when a positive voltage is applied to the gate.
RF power FETs require forward bias for optimum performance. The value of quiescent drain current (IDQ) is not critical for many applications. The MRF141 was characterized at
IDQ = 250 mA, each side, which is the suggested minimum
value of IDQ. For special applications such as linear amplification, IDQ may have to be selected to optimize the critical
parameters.
The gate is a dc open circuit and draws no current. Therefore, the gate bias circuit may be just a simple resistive divider network. Some applications may require a more elaborate
bias sytem.
GAIN CONTROL
Power output of the MRF141 may be controlled from its
rated value down to zero (negative gain) by varying the dc
gate voltage. This feature facilitates the design of manual
gain control, AGC/ALC and modulation systems.
MOTOROLA RF DEVICE DATA
PACKAGE DIMENSIONS
A
U
NOTES:
1. DIMENSIONING AND TOLERANCING PER ANSI
Y14.5M, 1982.
2. CONTROLLING DIMENSION: INCH.
M
1
M
Q
DIM
A
B
C
D
E
H
J
K
M
Q
R
U
4
R
2
B
3
D
K
J
H
C
E
SEATING
PLANE
INCHES
MIN
MAX
0.960
0.990
0.465
0.510
0.229
0.275
0.216
0.235
0.084
0.110
0.144
0.178
0.003
0.007
0.435
–––
45 _NOM
0.115
0.130
0.246
0.255
0.720
0.730
STYLE 2:
PIN 1.
2.
3.
4.
MILLIMETERS
MIN
MAX
24.39
25.14
11.82
12.95
5.82
6.98
5.49
5.96
2.14
2.79
3.66
4.52
0.08
0.17
11.05
–––
45 _NOM
2.93
3.30
6.25
6.47
18.29
18.54
SOURCE
GATE
SOURCE
DRAIN
CASE 211–11
ISSUE N
MOTOROLA RF DEVICE DATA
MRF141
7
Motorola reserves the right to make changes without further notice to any products herein. Motorola makes no warranty, representation or guarantee regarding
the suitability of its products for any particular purpose, nor does Motorola assume any liability arising out of the application or use of any product or circuit, and
specifically disclaims any and all liability, including without limitation consequential or incidental damages. “Typical” parameters which may be provided in Motorola
data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All operating parameters, including “Typicals”
must be validated for each customer application by customer’s technical experts. Motorola does not convey any license under its patent rights nor the rights of
others. Motorola products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other
applications intended to support or sustain life, or for any other application in which the failure of the Motorola product could create a situation where personal injury
or death may occur. Should Buyer purchase or use Motorola products for any such unintended or unauthorized application, Buyer shall indemnify and hold Motorola
and its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees
arising out of, directly or indirectly, any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that
Motorola was negligent regarding the design or manufacture of the part. Motorola and
are registered trademarks of Motorola, Inc. Motorola, Inc. is an Equal
Opportunity/Affirmative Action Employer.
Mfax is a trademark of Motorola, Inc.
How to reach us:
USA / EUROPE / Locations Not Listed: Motorola Literature Distribution;
P.O. Box 5405, Denver, Colorado 80217. 303–675–2140 or 1–800–441–2447
JAPAN: Nippon Motorola Ltd.: SPD, Strategic Planning Office, 4–32–1,
Nishi–Gotanda, Shinagawa–ku, Tokyo 141, Japan. 81–3–5487–8488
Mfax: [email protected] – TOUCHTONE 602–244–6609
ASIA/PACIFIC: Motorola Semiconductors H.K. Ltd.; 8B Tai Ping Industrial Park,
– US & Canada ONLY 1–800–774–1848 51 Ting Kok Road, Tai Po, N.T., Hong Kong. 852–26629298
INTERNET: http://motorola.com/sps
MRF141
8
◊
MRF141/D
MOTOROLA RF DEVICE
DATA